Call the superclass initializer in SerialTransport.
SerialTransport ultimately inherits from asyncio.transports.BaseTransport. The existing code did not call the superclass initializer, so subsequent calls to inherited methods such as SerialTransport.get_extra_info() would fail.
diff --git a/serial/aio.py b/serial/aio.py
index a4e8357..95cb880 100644
--- a/serial/aio.py
+++ b/serial/aio.py
@@ -21,6 +21,7 @@
class SerialTransport(asyncio.Transport):
def __init__(self, loop, protocol, serial_instance):
+ super().__init__()
self._loop = loop
self._protocol = protocol
self.serial = serial_instance